It has been known to end-splice copper or copper-alloy tapes by means of apparatus that inserts appropriate lengths of silver solder between the cut ends of said tapes while they are positioned over the flat surface of an electrode, lowering another electrode over the area to be spliced and then passing a sufficient current through the two electrodes. Such apparatus performs satisfactorily for small widths of soft copper as described in below named patents but if the copper or alloy is hard rolled or is very wide, consistently satisfactory splices may not be obtained due to buckling of the tape edges or, if the tapes are of fine gauge, areas where they overlap at the seam. Such buckling or overlapping is, of course, intolerable, if the tape is being fed into a punch press or the like.
In U.S. Pat. Nos. 4,563,563 and 5,125,559, issued to one of the applicants of the present invention, disclosures are made that are now part of the industrial art and may be described as part of the procedures herein practiced, but novel improvements, herein disclosed make it practical to apply these butt splicing procedures to hard or especially wide tapes.
A most important industrial application for butt splicing metal tapes is in the metal stamping and punching arts. A coil or reel of the metal tape is fed into the metal punch or stamping machine. After each actuation of the press, the tape is advanced a preset distance and the press actuates again. When the last of the tape leaves the reel, the process can only continue without interruption if a new real of tape is provided and the tail end of the earlier tape is butt spliced to the new tape. An accumulator storing a length of the tape gives the operator only a short time to make the splice. He must be present when the changeover is required, which makes him unavailable for other duties.